This invention relates to a driver side airbag membrane horn switch assembly. Driver side airbags are conventionally mounted on steering wheels along with horn actuating switch arrangements. A number of horn actuation switch assemblies have been proposed which suffer disadvantages and actuation inconsistencies when accommodating the tear lines in an airbag module cover. In such an airbag restraint system the airbag is forced out of the module in a predetermined manner through weakened areas or tear lines in the airbag cover or door. In order to accommodate and not interfere with the operation of weakened areas or tear lines in an airbag cover during deployment of the airbag, the membrane horn switch typically has been placed or located only on one half of the airbag cover or to the side thereof. However, this is not desirable, particularly in the event of an emergency where the vehicle occupant needs to be able to apply pressure to any portion of the airbag cover on the steering wheel in order to immediately actuate the horn. Emergency response time is limited if an emergency or accident is imminent, thereby requiring the provision of a large horn actuation area. If actuation of the horn membrane switch is to be possible over essentially the entire surface area of the airbag cover, the switch needs to be constructed of two separate and distinct sections. The horn switch would then require two separate wiring circuits if both halves of the cover were to be fully sensitive or responsive to actuation pressure on the cover. Otherwise, only part of the airbag door cover would be capable of operating the horn.
It would obviously be desirable to provide the potential for horn actuation over a larger area of the airbag cover without having to provide additional circuitry for both sides of the airbag cover or door. It is also desirable to provide a membrane horn switch that is easily and quickly activated over a significant portion of the airbag cover and yet does not significantly interfere with deployment of the airbag or opening of the cover door at the weakened area or tear line portions.
Accordingly, it is an object of this invention to provide a membrane switch which can provide a large horn actuation area that is easily and quickly actuated. It is another object of the present invention to provide a membrane switch which requires only a single wiring circuit to actuate the switch assembly. It is a still further object of the present invention to provide a membrane switch which permits a large horn actuation area that is quickly and easily actuated yet does not unnecessarily interfere with or prevent deployment of an inflatable airbag through an airbag cover or door having weakened areas or tear lines thereon when the membrane switch is positioned behind the horn actuation area of the airbag cover or door.